The update applies to systems running the BlackBerry Application Web Loader, a piece of software used to transfer software onto the handsets from a PC.
The company said that the issue was related to Microsoft's recent security update for Internet Explorer. The update concerns the ActiveX component used to connect the BlackBerry software to Internet Explorer 7.
According to RIM, the ActiveX component is vulnerable to a memory overflow error which, if exploited, could allow an attacker to remotely execute code on a targeted system.
The patch comes on the same day that RIM made a major investment to update the security of future BlackBerry devices, including the purchase of Canadian cryptography specialist Certicom.
The C$105m (£59m) deal concludes what had been a bidding war between RIM and VeriSign for Certicom and reflects a price roughly double that of RIM's initial offer in December.